Pump



Nov. 21, 1944. A -rRlpp 2,363,162

' PUMP 3 Sheets-Sheet l Filed Dec. 29, 1941 @www i N0v.z1, 1944. B. A.mp1 Y 2,363,162

P UMP Filed Deo. 29, 1941 3 Sheets-Sheet 2 B. A. TRIPP Nov. 21, 1944.V u

PUMP

Filed Deo. 29, 1941 5 Sheets-Sheet 3 crx ch 0o Syvum/viola Patented"Nav. 21, 1944 u l 1 UNITED sTATlizS-` PATENTOFFICE l rUMr` BenjaminA.Tripp, Knoxville,Tenn.` Application December 29, 19111, serial No;424,827 14 claims- (orfiosficirfff Y This invention relates to highpressure pumps, and more` particularly to a rotary pump of the radialcylinder type adaptedI especially for operat.-A

ing ahydraulic press.

One offthe objects ofthe invention is to provide1 a pump of suchconstruction asto prevent vibration of the pipe line caused by strokesof the pistons1 which is accomplished in my construction due mainlytothe fact` that two cylinders are always disch'argingat `the same timeat 901degreesintervals.` p `1 Another object is` to provide a pump, the`output of whichf has adeiinitelmaximum pressure whichmay be maintained,but not exceeded for each setting of a control member. 1 1 1' A furtherobjectv is to supply a pump of balanced character" which facilitateslubrication when 1ubricating11oil`1 is usedfas the- `pressure medium. 11 With the foregoing objects outlined and with other objectsin View`which will appear as the description proceeds, the invention consistsin the1 novel features hereinafter described in detail, illustrated inthe accompanying drawings, and more particularlyV pointed out in theappended 1 claims.

1 In thedrawings:

Fig. 1? is a side elevation, partly in vertical section, of my improvedpumpA 'structure shown 1in use with a1 hydraulic press. l 1 l Fig; 211s'a1transversevertical sectionalview of the pump on an enlarged1scale,and' shown partly in elevation; f l 1. 15 Fig. 31is1a verticallongitudinalsectional taken on the1line1`33 oil Fig. 2.1 1 1 Fig. 41 is`anenlarged transverse vertical sec--` tionalview of a1 detail?, takenon theline 4 4 of Fig.3. l 11 11 Referring to the drawings, designatesa1stationary tubular shaft' having a crank portion 16 atone end thereof.The opposite'endof the shaft is connectedflby ascrew threaded joint toan View, 1

ably secured in position by any suitable means l suchas a nut l1 havingthreaded engagement witnthe bushing H; For reinforcing purposes, struts|-8 4are arranged between the-peripheral portionl of the" plate I6, and1a brace collar"` `|`9 `which surrounds" anjdslidablyengages the`loushing H1.

For sealing purposes, a packingfring il` is arrangedlbetween the parts*1|10i and1 Il, andis engaged by ar threaded gland 2 l;

The drive sleeve may beturnedffby anysuitable means such as aL beltdriven pulley 212 keyedto thesleeve as indicated at 253i. 1 1

1'll1'1e drive sleeveis provided uatome end with a shoulderedflange24``which slidably engages the` ange I3. Between the1 flanged endofthe drive sleeve" andthestationarycrankshaft, there is a valve seatbushing 251 having-an internal.' frustoconical surface engaging `acorresponding surface at the exterior ofA the crankshaft.

VFour or more radially arranged cylinders 2e? 1 have their inner ends inthreaded' connection with Vadapter 'I1 that may-be connected by' al pipe8 to any meansforf utilizingtlieoutput of the pump,

in Fig. 3, the shaft supports` a1 rotatable drive 1 sleeve iii whichrotatesina reservoirbushing Il.

At oneend', the latter extends into' al reservoir lf2 and is providedwith anA outwardly extending flange i3' abutting a1 reinforcing platelllwhich in turn a-buts one of' the walls of the FronrFig; 2 it may beseen; that the disk 32 the shaft.

the drive sleeve,I and the inner ends1 ofl such cylinders cominunicate`by ports 21j either with an intake `groove 28 or `adiscl1argeg`roove129ofthe crankshaft; the groove' 28'communica`ting1with an inlet passageway3`0` of the shaft, and the groove 29 communicating with` an outletpassageway 3`| which is within11 thel shaft and' leads tothepipe B. Asbest shown in Fig. 4*, the grooves are so arranged with relation to thecylinders lthat two1 cylinders are in communication with the intakegroove while the other two cylinders are in communication withthedischarge groove. 1

of a master `connecting1 rod-33 is rotatably mounted upon thecrankportion of the stationary shaft so as to travel1 about an axis arrangedeccentri- `cally to the axisof the main portion of the shaft,-

and the master connecting rod 33 is preferably providedwith a centralbearing`134. A thrust plate 35` is held in Contact with the bearingportionof the master connecting rod 33 by means of athrust nut 36threaded on the crank portion of to the disk of the master connectingrod 33 and the outer end portion of each connecting rod is preferably`of `U-shape,1 as indicated at 39 (Fig. 3), soas to receive theheadportion 40 of a piston 4`|.` Obviously, thereisone pistonfor eachcylinder,` and the enlarged heads of the pistons slidably 1 androtatablyV engage pins 42 by Vwhich they are secured to thecrankconnectingjrods.

l'lhe pistons`,1cyli`nders and crank rods all ro- Other connecting rodsor linksifl` have their inner ends pivotally1 connected at 438 t tate inunison with the drive sleeve Ill, and they are preferably arranged in atwo-part housing 43 that is fixedly connected at 44 to the drive sleeveso as to rotate therewith. This housing of the main parts within thereservoir prevents turbulence, as best shown in Fig. 1, while at thesame time allowing the pressure medium within the reservoir to enter thehousing through a central aperture 45.

From `Fig. 3 itwill be noted that the stationary crankshaft hasa thrustflange 46 against which flange 41 of the valve seal bushing 25 presses,and

this contact and also the contact between the conical part of 5 and theconical inner surface of valve seal bushing 25 is maintained by themeans now to be described. f

A bushing 48 which has a press t with one end of the drive sleeve, and asliding flt on the stationary crankshaft, provides a recess for packing49 held in place by a packing nut 50. An anti-friction thrust assembly5| surrounds the stationary shaft and is pressed against the nut 50 bymeans of a coil spring 52, the compression of which may be adjusted by anut 53 in threaded connection with the crankshaft and which may besecured in xed position by a set screw 54.

As the oil used as a pressure medium may also serve as a lubricant, itmay travel :between the bushing I l and drive sleeve l for the purposeof lubricating moving parts, and to prevent such oil from leaking, Iarrange an internal annular groove 55 within the bushing so that it maydischarge such oil through a relief line 58 back into the reservoir. Aport 56 which extends through the drive sleeve from the shaft to thebushing Il, provides a passageway and prevents a high pressure frombuilding up against packing ring 49. A union fitting or coupling 51 maybe employed in returning such oil to the reservoir by means of a pipe 58connected at one end to the union and at its other end to a three-wayvalve 59 which in turn lis connected by a pipe 60 to another union 6Ithat is connected to the lower portion of the reservoir. To permitinspection of the oil, the three-way valve, as shown in Fig. 1, may beconnected to a tube 62 which leads to the top portion of the reservoirand has an inspectie-n element 63 interposed therein. Any fluid can bepumped by this invention and its use will not be restricted to pumpingoil, or for operating hydraulic presses. l

In operation, a suitable prime mover turns the pulley 22 which rotatesthe drive sleeveI i0. As the latter carries the cylinders, and they turnas a group about the axis of the main portion 'Y of the shaft 5, thepistons 4| will be moved radially in and out relatively to said axisbecause of the fact that the connecting rods are operably connected tothe bearing 34 which rotates eccentrically with regard to said axis. Asthe cylinders travel, the pressure medium in the reservoir will be drawnthrough 30 and 28 into the cylinders as the pistons therein moveoutwardly. Then, as the pistons move inwardly, the pressure medium willbe forced through 29, 3l and 8 to the hydraulic press 9. Of course, thepressure medium will be returned from the press to the reservoir by anysuitable means, not shown. which can be set in any position and heldthere by the set screw 54, presses against the compression spring 52. Asthe inner surface of the valve seat bushing is frusto-conical, it has arunning t on the somewhat longer tapered section of the portion of thecrankshaft which it In such operation the thrust nut 53,Y

l' backl to the reservoir.

surrounds. They t perfectly throughout their surface of contact. Underthe high pressures used, there will be a slow leakage of the pressuremedium between these surfaces, flowing both to the left and right (Fig.3) from the ports 21 during discharge. This leakage pressure mediumexerts a pressure substantially perpendicular to the two frusto-conicalsurfaces. The horizontal component of the pressure on the shaft 5 tendsto force it ,to the left, and,v similarly, part 25 is forced toward theright. 'Ihe compression spring 52 will establish a balance with theforce moving the crankshaft to thefleft, and thepressure gauge (notshown) will hold steady even when the entire output of the pump isby-passing direct to intake port 28, or back into the reservoir by goingto the left between iianges 46 and 41, or through relief line 58, due totheV press having reached the end of its stroke. The vcrank shaft thusacts as a relief valve when the hydraulic press comes to the end of` itsstroke, by moving to the left and thus creating a passageway between theconical inner surface of the valve seat 25 and the outer surface of thecone shaped part of the crankshaft through which the'V pressure mediumcan pass.

My improved pump is particularly advantageous for use with hydraulicpresses employed in the manufacture of plastics such as Bakelite, whichcome in powder form and have to be compressed just the right amount tobecome solid and almost unbreakable. 'Ioo 4much pressure injures ythequality of the product', and as my pump automatically relieves thepressures when it reaches the desired maximum, it is manifest that thepump is especially useful with such presses.

It will be observed that oil passing to the right by leakage orotherwise from the valve ports 21 during discharge, passes between theparts 5 and I0, then through the hole or holes 56 to the exterior ofthe' driving sleeve I0, then via the groove 55 around the inside of thebushing Il until it reaches the union 51 from which it passes Thisstructure prevents a high pressure from building up against the packingring 49, which I found would not form an effective seal without thisrelief provision.

There is no vibration of the pipe line 8 caused by the piston strokes inmy pump, because there are always two cylinders discharging at thesametime at degree intervals.

Rotation of the pump being tothe right (Fig.

`2), no special provision has to be made to prevent the rotation of theinner group of parts except the use of right hand threads on the adapter1 and the crank shaft 5.

While I have disclosed what I now consider to be a preferred embodimentof the invention in such manner that the same may be readily understoodby those skilled in the art, I am aware that changes may be made in thedetails disclosed, without departing from the spirit of the invention,as expressed in the claims.

What I claim and desire to secure by'Letters Patent is:

1; In a structure of the character described, a crankshaft member, asleeve member surrounding the crankshaft member, one of said membersbeing rotatable relatively to the other, means for rotating therotatable one of said members, a plurality of radially disposedcylinders xedly connected to the sleeve member, a valve sleeve havingports, one for each cylinder; positioned between said members androt'atablewith one of! said" members, the ports` ofl Athe 'valve sleevecommunicating with the inner ends oil the cylinders, an intakepassageway inthe crankshaft having: a portionA extending" transverselythereof and otl such length as to-communicate simultaneously with aplurality or adiacent' portsi off the valve. sleeve, adischargepassagewayl in the crankshaft member having/a portion.:`extending transversely thereof andof' such length as. to communicatesiinultarreously:,with` a` plurality of ports:` off the valve sleeve,pistonsV slidably fitted inthe4 cylinders,` means operatively connectingthe outer ends` ofthe pistonsto thecrankportion oit-the crankshaftmem-ber, whereby `the pistons are'` torced to= reciprocate due:` to.rotation `et one oit said members; one: or said members: being san:membersbeing axially-movable relatively to the other one of saidmembers, yieldingl means functioning to` hold' said members againstaxial -movement and tor-maintain the contact between said truste-conicalsurfaces, andi meansfor discharging a pressure medium from between saidmembers.

`la In apump; a crankshaft: member,a sleeve member surround-ing thecrankshaft member, one

of said members beingrotatablerelatively to the other, means: foriturning oneof said members, a

axially movable relatively to. the other onewof said members, yielding`means` :functioning` to holdsad= membersagainst axial? movement, andVmeans for dischargingpressureimedium from be`` y tween said members;` ii 2l. In-` a struoturev off' the character described, a

pluralityy offradiallywdisposed cylinders fixedly connectedto` thesleeve; member, a valvesleeve having ports",` one: for each cylinder"positioned between the crankshaft" and the sleeve member, l androtatablewi'thone ofsaidl members, theports of thefvalvesl'eevecommunicatingwith theinner` i ends of the cylinders, an intake `means inthe crankshaft member ,extending transversely therecrankshaft member, asleeve member surroundinawthe` crankshaft member and:` of' `less@`length than therlatter, one or said members beingV rotatable`relativelyto thel other` means: for rotating therrotatable one of saidinm-imbers-,-` aplurality of'l radially" disposed` cylinders xedly`connected toionefend portion. or the-:sleeve member and ar- Arangedadeacent to `the crank: portion oi `the ioranksl'iart` member;` a.valve: sleeve, having: ports,` Voneeizorv each cylinder-r positioned.betweeizrA the members: and: rotatable. with one. or said `meinbersgthaportsi of' the valve sleevel communicatingfwithr the?, inner ends;vof' the` cylinders, an in,-

` take passagewayYr in `the crankshaft:member` havingaportion extendingtransversely thereof and `ot suolr length. astolcornmunieatesimultaneously withla plurality or adiacentmports of the:valve sleeve. a ,cli'soharge` passageway in` thecrankshart; member.'haring; a1 portionextending trans;- verselythereoi and` or suoh length;as toY communicatev simultaneously' with. a plurality oi ports` or theivalve sleeve;A pistons slidably iitted `in,` the, cylinders; means-r`operatively `connecting l the outer: ends:` ofiltlref` pistons', tofthecrank por tiener said;` crankshaft, iriieinlwr,` ,whereby the fpi'stons:arei turned; to reciprocate` diie: tol rotation oni one of? saidmembers, one. or` saiidtmembers being axial/ly,-` movable-`relatimelivito the other. yielding: means` for` yieldingltt retaining.onen, of

said members: against axial;` movementrelatively `tothe-other, and;meansror discharging-:pressure medium trom. between saidmembers.`

3'. Im afpump',. aistationary crankshaft' member, a sleevey membersurrounding, and rotatable: on l 'the crankshaft member, meansgforturning the sleeve,` member; a` plurality ofi radially disposedcylindersv xed-ly connected toi theL sleeve member, a'. valve` sleevehhaving porta, one: for each; cylinder;` Vposition-edi between. the:crankshaft and'` the sleeve, memberw and rotatable with the sleeveeating-1 with. ther inner' ends:l ofc the` cylinders; an

intakea meansfinthe. crankshat memberv adapted tocommunioatewiththeportsaof thetvalvel-sleeve, a1 discharge means: in` the. crankshaftmember adapted to.` communicate with? the: ports or the valve sleeve,pistons: slidablv` iittedrin the: cylinders; vmeansoperativelyfconnecting theaouter ends votthelpistons:tofthelorankportion `of said crankshaft memberpwherebythelpistons arerorcedto reciprocate; due: to rotation; of` said: sleeve member,-theivalve sleeves and crankshaft member having; contnoting;`frustof-conioalsuriaces, onel of of and of such length as to;communicate`-simuli, taneously with a plurality of.'` adjacentjports ofthey valve sleeve, an intake passageway extending into one endl' of the.crankshaft member and` communicating with said. intake means, adischarge means in thel crankshaft member extending l transverselythereof` and of suchA a length as to` communicate simultaneously with apluralityA oi ports; off the `valve sleeve, :a discharge passagewaycommunieatingl with the Vdischarge means and member; therportszorthevalve-,sleeve communi;-`

extending through the crankshaft member in a `directiontoward theopposite end ofthe crankshaft member',` pistons slidablyiitted` in thecylinders,- means operatively connecting the outer endsoff'theipistonstothe crank portion of said crank'- shaft member, wherebythe pistons are forced to` 5.` Ina pump, astationary'crankshaft, adrivesleevefs'urrounding the crankshaft', a stationary bushing in whichthe drive sleeve is journaled,

`and through which the drive sleeve extends,

means for turning the drivev sleeve positionedat` `one endl` of thebushingaplurality of' radially disposed cylindersfixedly connected tothedrive sleeve and: arranged at the opposite end` ofY the bushing, a valvesleeve havingportsonefor each` cylinder positioned? betweenl thecrankshaft and thedrive sleeve and rotatable with the latter, the portsotithe valve sleeve communicating with the inner ends of' the cylinders,anl intake groove in the crankshaft `extending transversely thereof 'andof such length as to communicate simultanei `ously with.` a` pluralityofadjacent ports of `the l ,l

valve sleeve', an intake passageway extending into one endlof'thecrankshaftand communicate ing` witlrisaid.` groove, a dischargegroove in the crankshaft extending transversely thereof and of such` a4length as to@ communicate simultaneously with a plurality or ports ofthe valve sleeve, Va `discharge passageway communicating with thedischarge groove andl ,extending through `the crankshaft inV a1direction away from saidcylinzi the pistons' to the cranky portion ofsaid. shaft,

ders; pistons` slidably tted in the cylindersf andl means operativelyconnecting the outer ends of whereby the pistons. arejforcedtofreciprocate duetorotationuof the drive'sleeve.

f 6;. In a pump, astationarycrankshaft, .a drive` sleeve surrounding thecrankshaft, a 'stationary bushing in which the drive sleeve is journaledand through which the drive sleeve extends,

means for turning the drive sleeve positioned at one end of the bushing,a plurality ofY radially disposed cylinders xedly connected to the drivesleeve and arranged at the opposite end of the bushing, a valve sleevehaving ports, one for each cylindeigl-positioned between the crankshaftand the drive sleeve and rotatable with the latter; the ports of thevalve sleeve communicating with the inner ends of the cylinders, anintake groove in the crankshaft extending transversely thereof and ofsuch length as to communicate simultaneously with a plurality ofadjacent ports of the valve sleeve, an intake passageway extending intoone end of the crankshaft and communicating with said groove, adischarge groove in the crankshaft extending transversely thereof and ofsuch a length as to communicate simultaneously'with a plurality of portsof the valve sleeve, a discharge passageway communicating with thedischarge groove and extending through the crankshaft in a directionaway from said cylinders, pistons slidably fitted in the cylinders,means operatively connecting the outer ends of the pistons to the crankportion of said shaft, whereby the pistons are forced to reciprocate dueto rotation of the drive sleeve, said crankshaft being axially movablerelatively to the drive sleeve, means for yieldingly holding thecrankshaft against axial movement in one direction, and means fordischarging pressure medium from between the crankshaft and drivesleeve.

7. A structure of the kind claimed in claim 1, in which the valve sleeveand crank shaft member have contacting frusto-conical surfaces.

8. In a structure of the character described, a reservoir to contain apressure medium, a stationary bushing connected to the reservoir andhaving a bore communicating with the interior of the reservoir, a drivesleeve journaled in and extending through the bushing, radial cylindersxedly secured to one end portion of the sleeve and arranged in thereservoir, means secured to the opposite end portion of the sleeve forturning the latter, a stationary crankshaft extending through the sleeveand having a crank end portion positioned within the reservoir, avalvesleeve having ports, one for each cylinder, positioned rbetween thecrankshaft and the drive sleeve and rotatablewith the latter, theportsof the valve sleeve communicating with the inner ends vof the cylinders,an intake passageway communicating with the reservoirand arranged tosimultaneously supply the pressure medium from thereservoir to aplurality of said cylinders, a discharge passageway extending throughthe main portion .of the crankshaft and arranged to simultaneouslydischarge the pressure medium from a plurality of said cylinders,pistons slidably fitted in the cylinders, and means operativelyconnecting the louter ends of the pistons to the crank portion of saidshaft, whereby the pistons are forced toreciprocate due to rotation ofthe drive sleeve.

9. In a structure of the character described, a reservoir to contain apressure medium a stationary bushing connected to the reservoir andhaving a bore communicating with the interior of. the reservoir, a drivesleeve journaled in and extending through the bushing, radial cylindersxedly secured to one end portion of the bsleeve and arranged in thereservoir, means secured to the opposite end'portion of the sleeve forturning the latter, a stationary crankshaft extending through the sleeveand having a crank end portion positioned within the reservoir, a valvesleeve having ports, one for each cylinder, positioned between thecrankshaft andthe drivesleeve and rotatable with the latter, the portsof the valveV sleeve communicating with the inner ends 'of thecylinders, an intake passageway communicating with the reservoir andarranged to simultaneously supply the pressure medium from the reservoirto a plurality of said cylinders, a discharge passageway extendingthrough the main portion of the crankshaft and arranged tosimultaneously discharge the pressure medium from a plurality of saidcylinders, pistons slidably fitted in the cylinders, means operativelyconnecting the outer ends ofthe pistons to the crank portion of saidshaft, whereby the pistons are forced to reciprocate due to rotation ofthek drive sleeve, and a circular housing rotatable with the drivesleeve and enclosing said cylinders and said connecting means.

10. In a structure of the character described, a reservoir to contain apressure medium a stationary bushing connected to the reservoir andvhaving a bore communicating with the interior of municating with theinner ends of the cylinders,

an intake passageway communicating with the reservoir and arranged tosimultaneously supply the pressure medium from the reservoir to aplurality of said cylinders, a discharge passageway extending throughthe main portion of the crankshaft and arranged to simultaneouslydischarge the pressure medium from a plurality of said cylinders,pistons slidably fitted in the cylinders, means operatively connectingthe outer ends of the pistons to the crank portion of said shaft,whereby the pistons are forced to reciprocate due to rotation of thedrive sleeve, said crankshaft being axially movable relatively to thedrive sleeve, means for yieldingly holding the crankshaft against axialmovement in one direction, and means for leading'the'pressure mediumfrom between4 the crankshaft and drive sleeve to the reservoir.

11. In a structure of the character described, a reservoir to contain apressure medium, a stationary bushing connected tothe reservoir andhaving a bore communicatingv with the interior of the reservoir, a drivesleeve journaled in and extending through the bushing, radial cylindersxedly secured to one end portion of the sleeve and arranged in thevreservoir, vmeans secured to the opposite end portion of the sleeve forturning the latter, a stationary crankshaft Vextending through thesleeve and having a crank endportion positioned within the reservoir, avalve sleeve having ports,one for each cylinder positioned between thecrankshaft and the drive sleeve and rotatable with the latter, the portsof the -valve sleeve communicating with the inner ends of the cylinders,an intake passageway communicating with the reservoir and arranged'tosimultar 2,363,1e2` ,i

neouslysupplythe pressure medium from` the reservoir to a vplurality ofsaid cylinders, a discharge passageway extending through the mainportion of the crankshaft and arranged to simultaneously discharge thepressure medium from a plurality of` said cylinders, pistons slidablyfitted inthe cylinders, and means operatively connect- 13. In astructure of the characterdescribed, a

crankshaft member, a sleeve member surrounding the outer ends ofthepistons to the crank i portion of said shaft, whereby the pistons areforced to reciprocate due `to rotation' of the drive sleeve, the lastmentioned means comprising a master crank rod rotatably mounted on lthei crankshaft and connected to one of saidfpistons, i and other rodspivotally connected to` the `master crank rod and `to the other pistons.

12. In a structure of the character described, a reservoir to contain apressure medium, a stationary `bushing connected to the reservoir andhaving a bore communicating with theinterior of the reservoir, a drivesleeve journaled iii" and extending through the bushing, radialcylinders iixedly secured to one end portion of the sleeve and arrangedin the reservoir, means secured to the opposite end portion of theAsleeve for` turning the latter, a stationary crankshaft extendingthrough the sleeveand havingl a `crank end portion` positioned withinthe reservoir, a valve ing the crankshaft member, one of said members ibeing rotatable relatively to the other, means for` rotating the`rotatable one of said` members, a

plurality of `radially disposed cylinders Xedly `connected to` the`sleeve member, a valve sleeve having ports, one foreach cylinderpositionedA between said members and rotatable with one of I saidmembers, the portsv of the valve sleeve communicating with the innerends of the cylinders,

an intake passageway in the crankshaft having a i portion extendingtransversely thereof` and of `such .length as to communicatesimultaneously with a pluarltiyof` adjacent ports of the valve sleeve, adischarge passageway in the crankshaft member having a portion extendingtransversely` thereof and of such length as to communicate isimultaneously with a plurality of portsof the `valve s1eeve,pistonsslidably tted in the cylinders, means operativelyconnecting the outerends` i of the pistons to the crank portion of the crankshaft member,whereby the pistons are forced to i reciprocate dueto rotation of one ofsaid mem` bers, one of said members being axially movable relatively tothe other one of said members, yielding means functioning` tov hold saidmembers against axial movement, means for discharging the pressuremedium from between said members, and packingmeans arranged at one endof the sleeve member for sealing the space be- `discharge passagewayextending through the j` main portion of the crankshaft and arranged tosimultaneously discharge the pressure medium from a plurality of said"`cylinders, pistonsslidably; fitted in the cylinders,` means operativelyconnecting the outer ends of the pistons to the tweensaidmembers at thatend of the sleeve K member.

`14. In a pump, a stationary shaft,V a rotatable shaft surrounding andmountedon the stationary shaft, saidstationary shaft having afrustoconical portion, intake and discharge passageways in saidfrusto-conical portion, valve means rotatable with the rotatable, shaftand having a frusto-conical surface rotatable on thefrustoconicalportion ofthe stationary shaft,` one of crank portion of said shaft,whereby the pistons l are forced to reciprocate due to rotation of the i`drive sleeve, said crankshaft `being axially movable relatively to thedrive sleeve, means mounted said shafts being axially movable relativelyto` the other to provide a slight space betweenthe i frusto-conicalsurfaces, ports extending through on thecrank shaft and engageable withthe drive sleeve for yieldingly` holding the crankshaft` against axialmovement in .one direction, and

` means for leading the pressure. medium from between the crankshaftanddrive sleeve to the reservoir,` the means connecting the outer endsof the pistons to the crankshaft being movable with the crankshaftrelativelyto the pistonswhen the crankshaft moves axially.

said valve meansand arranged to communicate` with said'intake anddischarge passageways, cyl- `inders rotatable with the rotatable shaft,pistons arranged to reciprocate in the cylinders, means for causingreciprocation of thepiston's when the rotatable shaft is turning,yielding means functioning to normally hold the shafts against relativeaxial movement, and means for discharging a pressure medium from betweensaid shafts.

` BENJAMIN A. "rRIPP,

